Cyclization Reactions of Dianions in Organic Synthesis

Langer, Peter; Freiberg, W.

doi:10.1021/cr010203l

Cited by 141 publications

(52 citation statements)

References 125 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…16 The treatment of β-ketoester 16 with at least two equivalents of strong base such as LDA generates the corresponding dilithio compound 17. For kinetic and thermodynamic reasons, this kind of dianion reacts with electrophiles preferentially at the γ position.…”

Section: Introductionmentioning

confidence: 99%

1,3-Dicarbonyl compounds in stereoselective domino and multicomponent reactions

Bonne¹,

Coquerel²,

Constantieux³

et al. 2010

Tetrahedron: Asymmetry

164

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

1,3-Dicarbonyl compounds in stereoselective domino and multicomponent reactions

Bonne¹,

Coquerel²,

Constantieux³

et al. 2010

Tetrahedron: Asymmetry

164

View full text Add to dashboard Cite

“…The construction of medium- (8-to 11-membered) and large-ring (> 12-membered) macrocycles is generally difficult to achieve because of entropy and enthalpic contributions 9,10. To overcome these contributions in macrocyclic synthesis three modes of cyclization are commonly used and they are distinguished by the position of the reacting groups: (1) the end-to-end, (2) the end-to backbone, and (3) the backbone-to-backbone cyclizations 11.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, lactone formation via a π-allylpalladium intermediates has been reported 14. Cyclization via a carbon-carbon based strategy initially began with nucleophile- and electrophile-promoted methods,9 and later radical and metal-catalyzed cyclizations appeared 15. More recently metal-catalyzed cyclizations have been performed using the ring-closing metathesis (RCM) 16.…”

Section: Introductionmentioning

confidence: 99%

Development of a General, Sequential, Ring-Closing Metathesis/Intramolecular Cross-Coupling Reaction for the Synthesis of Polyunsaturated Macrolactones

Denmark

Muhuhi

2010

J. Am. Chem. Soc.

View full text Add to dashboard Cite

A general strategy for the construction of macrocyclic lactones containing conjugated Z,Z-1,3-diene subunits has been is described. The centerpiece of the strategy is a sequential ring-closing metathesis that forms an unsaturated siloxane ring followed by an intramolecular cross-coupling reaction with a pendant alkenyl iodide. A highly modular assembly of the various precursors allowed the preparation of unsaturated macrolactones containing 11-, 12-, 13-and 14-membered rings. Although the ring closing metathesis process proceeded uneventfully, the intramolecular cross-coupling required extensive optimization of palladium source, solvent, fluoride source and particularly fluoride hydration level. Under the optimal conditions (including syringe pump high dilution), the macrolactones were produced in 53-78% yield as single stereoisomers. A benzo fused 12-membered ring macrolactone containing an E,Z-1,3-diene unit was also prepared by the same general strategy. The E-2-styryl iodide was prepared by a novel Heck reaction of an aryl nonaflate with vinyltrimethylsilane followed by iododesilylation with ICl.

show abstract

“…1,2 The less-substituted conjugated dienes can be prepared by Wittig-type olefination 3 or transition-metal-mediated coupling reactions of the deliberately functionalized precursors. 1,4 However, multiply substituted butadiene-containing mono-or bis-electrophiles are difficult to access by such methods.…”

Section: Introductionmentioning

confidence: 99%

Synthetic Methods for Multiply Substituted Butadiene-Containing Building Blocks

Xi¹,

Zhang²

2008

Synlett

View full text Add to dashboard Cite

Conjugated organic systems have attracted much attention because new materials and functional structures can be expected from them. 2,4-Dienes mono-and disubstituted with electrophiles at the 1-and 1,6-positions, respectively, containing a butadienyl-conjugated skeleton and one or two terminal functional groups that can be manipulated, represent one of the most useful building units for the preparation of both cyclic and linear conjugated compounds. This account summarizes the synthetic methods available for multiply substituted butadiene-containing mono-or bis-electrophiles.

show abstract

Cyclization Reactions of Dianions in Organic Synthesis

Cited by 141 publications

References 125 publications

1,3-Dicarbonyl compounds in stereoselective domino and multicomponent reactions

1,3-Dicarbonyl compounds in stereoselective domino and multicomponent reactions

Development of a General, Sequential, Ring-Closing Metathesis/Intramolecular Cross-Coupling Reaction for the Synthesis of Polyunsaturated Macrolactones

Synthetic Methods for Multiply Substituted Butadiene-Containing Building Blocks

Contact Info

Product

Resources

About